massive coverage. the degree of difficulty securing an area like this. >> yeah, mike, you're absolutely right. the fact is, you can't hardened the route of 26 miles, you can't harden an entire city. events like the super bowl, you can obviously do different levels of protection and go out and have no-fly zones and screening and metal detectors for people coming in. and all of that reduces, again, the chance of a really large-scale attack. something like a marathon route, it's impossible to do that other than in some very, very highly secure areas, potentially the start, the finish, official areas. but along that route, no matter how many soldiers in blue, the boston police department, massachusetts state police you line up, it's virtually impossible to keep everybody safe. and, again, i think what this requires is you do the best you can. you reduce the casualties, you try to find this before the act.